Multiple stage pulverizing and dehydrating tube mill



May 17, 1949. w. L. McGEHEE 2,470,315

MULTIPLE STAGE PULVERIZING AND DEHYDRATING TUBE MILL Filed April 29, 1944 2 Sheets-Shet 1 INVENT OR.

//aae L. Mafia/fee BY @4 TTOFNEK May 17, 1949. w. L. MGGEHEE 2,470,315

MULTIPLE STAGE PULVERIZING AND DEHYDRATING TUBE MILL Filed April 29,- 1944 2 Sheets-Sheet 2 IN VENT OR. //d6 L. Mafia/Yea a T TOR N E )4 Patented May v17, 1949- UNITED STAT-ES ,rA'rsur orr cs I 2,410.:151 I v \MUL'I'IPLE STAGE .nsnrnaa-rnvo roan MlLL Wallace L. McGehee, Qity, Ho. Application April as, 194;, sunrna ssazvs cim (c1. 241-64) This invention relates to dehydrating equipment of, the character adapted to remove moisture from such solids as lend themselves to being comminuted in the process of drying,

The primary aim of this invention is the provision of a continuous flow dehydrator, having a rotatable cylindrical body disposed horizontally and separated intoia number .of divisions,, each capable of acting upon" the material inja manner insuring thorough, ancient. and rapidtreatment efiecting the removal of moisture.

An important aim -of this inventionis to provide a dehydrator of the aforementioned type,

wherein one of the divisions of the-cylinder is equipped withback-feeding van-es to establish a counter-flow of such material as is not'thoroughly dried when it reaches a zone a iacent to the outlet pipe.

The hollowcylinder 12 removes the dried, comminuted material, is mounted 'uponrollersl6, rotatabl ioumalled in bearingsis, mounted on foundations 20.

,Rollers-f it are .flanged to receive annular v tracksdzlandasjhe cylinder ll rotates about i- .jprecluded;

m roweris fimpartedto cylinder u through the it l usit in endwise, displacement is medium of a conventional-electric motor 24 that v ft. 'inxlength and 6 ft. in

A yet further aim of this invention is to pro vide a dehydrator of the "continuous flowstype having as a portion thereof, two adjacent subdivisions, one having feed-back vanes therein,

and the other having shovels and grindingballs.

, driv'es' a train of gears 28, V meshwith the one of which is in ringgear acircumscribing the cylinder- 'l ladjacentits longitudinal central portion: v i

In practice. the-cylinder is substantially '60 g diameter. It is separatedinto a'number of divisions through the medium of annularpartitions ll, 32 and 34 respectively. partitions are ring-shaped and extend inwardly a short distance from the annular inner surface of cylinder I, The width ofthese. said partitions ".12 and 34 should be to insure a pulverizing action on the fed-back substance and a lifting of the pulverized material to a place within the hot gases as they approach the outlet pipe.

Other objects of the invention will appear during the course of the following specification, referring to the accompanying drawing, wherein: Fig. 1 is a side elevational'view of a continuous flow dehydrator embodying the. present invention. Fig. 2 is a longitudinal central fragmentary sectional view through the dehydrator. I Fig. 3 is an end elevational view thereof. Fig. 4 is a cross sectional view taken online IV-IV of Fig. 2, looking in the direction of the arrows.

substantially 12 in. to provide an opening 36 through partition 3|, an opening 38 through partition 32 and an opening lll through partition 84. I The first division nearest the inlet conduit 42 for hot gasesor products of combustion, is des-' Fig. 5 is another cross sectional-view taken on 7 its sub-divisions is such as to insure thorough removing of moisture as the materialbeing treats ed passes from the feed chute It to the outlet pipe I2.

' ignated by the numeral 44 and is a preheating chamber having a length of substantially 8 ft. In some instances, balls I are used to insure a comminuting-action or a breaking up of such materials as are starchy or sticky; A preheating of thematerial occurs in thi chamber 44, and since the pressure or velocity'o! the incoming products or combustionare relatively great in this chamber, the material being treated is carried into the main-drying compartment 48 as it is reduced in weight. A reduction of surface moisture here permits a build-up of material on lifters 50.

a marginal, innermost end 54 that precludes the This main'drying compartment is substantially 16ft. in lengthand under certain conditions, must have radial lifters 50. These lifters 50 are shown insection in Fig. 5, and each comprises a radial portion 52 that terminates in an inclined escape of material from each lifter until after thelifters have reachedthe uppermost point in their'pathof travel.

Asthe material is lifted and dropped by ravity' across opening in partition 32, it is moved toward the outlet pipe I! and into the classifying and drying section II, wherein is positioned a number of radial shovels ll, formed and disinto which feed chute directs the material and from which outlet pipe posed as clearly illustrated in Fig. 6." These shovels have their outer ends spaced inwardly from the face of the wall of cylinder ll to provide room for balls 60.

This classifying and drying section 56 is substantially 18 in. in width and confined between partitions 32 and 34. 'The balls 80 and shovels 58 therein cooperate with a series of inclined vanes 62 in the air-flotation and back-feeding chamber 64. These vanes 62 cause a counterflow of such material as will lie against the wall action of gravity removes the material to a point where it may again be acted upon by vanes 62.

The moisture content of the material passing through outlet pipe l2 may be determined by the position of adjustable pipe 66, telescoped with outlet pipe I! and held in a predetermined set condition by set bolt 88. When pipe 66 is moved outwardly to dispose a lesser amount of its length in chamber 64, the material escaping from the dehydrator is drier than when the pipe 66 is moved inwardly to the position illustrated in Fig. 2. In this position, the material withdrawn from the dehydrator has a higher moisture content than when the pipe 66 has its inner end closer to the end wall of cylinder I.

Feed chute III has its outlet end at the zone of juncture between the hot gas inlet conduit 42 and the end of the cylinder so that material entering cylinder ll through feed chute ill, will not have an opportunity of settling in preheating chamber 44 without being dispersed by the blast of heated gases enteringconduit 42.

Outlet pipes l2 and 66 are preferably made to be 28 in. in diameter-and inlet conduit 42 should be substantially the same diameter to insure effective throughput of material being treated. A suction fan 10 in connection with pipe i2, is operated by motor 12 and this fan 10 is connected to a cyclone separator 14 through the medium of a conduit 16, in conventional manner.

The temperature of the gases entering conduit 42 should be substantially 700 F., to the end that dehydration of such substances as alfalfa may be effectively accomplished after the full length of cylinder M has been traversed. The temperature at the outlet pipe I! will be about 180 F., but since these figures are examples to show the temperature differential between the ends of the cylinder, and further since the character of the material being treated may require a variation in the temperature of the flue gases introduced through pipe 42, it is necessary to determine requirements in this respect before operating the dehydrator.

Balls 46 and 60 may not always be needed. and therefore, the mention thereof is to indicate that in many instances they may advantageously be used in chambers 44 and 56. Light, flaky substances are sometimes treated without the use of radial lifters 50 in compartment 48 and their use, therefore, is not essential sofar as the function of the specially formed divisions of the cylinder designated by the numerals I6 and 64.

Having thus described the invention. what is claimed as new and desired to be secured by Letters Patent is:

1. A continuous flow dehydrator of the character described, comprising a rotatable cylinder having its longitudinal axis disposed horizontally;- means for rotating the cylinder; a hot gas inlet conduit axially disposed at one end of the cylinder; an outlet pipe axially positioned through the other end of the cylinder; means for feeding material to be dehydrated into said cylinder adjacent said hot gas inlet conduit: a suction fan in communication with the outlet pipe to create a current of gas through the cylinder from the inlet conduit to the outlet pipe; and a plurality of partitions setting off a series of divisions within the cylinder, each of said partitions being an annulus and extending radially inwardly from the wall of the cylinder, whereby to present an opening for the passage of the material being dehydrated, from one division of the cylinder to the next, the division at the end of the cylinder having the outlet pipe therethrough having longitudinally inclined vanes therein disposed to feed material in a direction counter to the direction of flow of hot gases through the cylinder and against the proximal partition, said vanes forming a number of opensided, elongated stalls in direct communication throughout their lengths with the interior of the said cylinder and the current of hot gases passing through the latter.

2. A continuous flow dehydrator of the character described, comprising a rotatable cylinder having its longitudinal axis disposed horizontally: means for rotating the cylinder; a hot gas inlet conduit axially disposed at one end of the cylinder; an outlet pipe axially positioned through the other end of the cylinder; means for feeding material to be dehydrated into said cylinder adjacent said hot gas inlet conduit; a suction fan in communication with the outlet pipe to create a current of gas through the cylinder from the inlet conduit to the outlet pipe; and a plurality of partitions setting off a series of divis'ions within the cylinder, each of said partitions being an annulus and extending radially inwardly from the wall of the cylinder, whereby to present an opening for the passage of the material being dehydrated, from one division of the cylinder to the next, one of said divisions having a number of grinder balls and a plurality of radially disposed shovels between the partitions forming that division, said shovels each having their outer ends spaced from the inner annular surface of the cylinder wall to allow free movement of the balls along the inner face of the wall of the cylinder and between the partitions forming the division containing the balls, said shovels each aving its inner marginal portion forwardly a gled out of the major plane of theshovel to retain the lifted material thereon until the remaining portion of the shovel passes a vertical position at the uppermost part of its path of travel.

3. In a continuous fiow dehydrator of the character described, a horizontally disposed cylinder having an inlet and an outlet opening, said openings being axially disposed at opposite ends of the cylinder; a plurality of annular partitions having openings on the axis of the cylinder to setoi'f a number of divisions in the cylinder, means for feeding material to be dehydrated into said cylinder adjacent said inlet opening and means for directinga current of hot gases through the cylinder from the inlet opening to the outlet openversal of flow 01 some of the material being treat- 5 ed alter the same has travelled through a portion of length of the cylinder and then dropped between the vanes, said vanes forming open-sided stalls in direct communication with the interior of the cylinder, the vanes terminating at the in- 10.

nermost ends thereof adjacent a proximal partition for dumping said reverse flow material into another of the divisions.

4. In a continuous flow dehydrator of the character described, a horizontally disposed cylinder having an inlet and an outlet opening, said openings being axially disposed at opposite ends of the cylinder; a plurality of annular partitions having openings on the axis of the cylinder to set off a number of divisions in the cylinder, means for feeding material to be dehydrated into said cylinder adjacent said inlet opening and means for directing a current of hot gases through the cylinder from the inlet opening to the outlet opening; a series of inwardly-directed, radial,

longitudinally-inclined vanes secured to the inner wall 0! said cylinder and disposed in one of the divisions a jacent to the outlet opening to cause reversal of flow of some of the material being treated after the same has travelled through a portion of length or the cylinder and then dropped between the vanes, said vanes forming 6 open-sided stalls in direct communication with the interior of the cylinder, said one division having the vanes therein being provided with an outlet pipe projecting thereinto from the outlet opening of the cylinder to a point between the ends or the said one division, said vanes extending the full length or the said division.

WALLACE L. McGEHEE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 474,490 Walter May 10, 1892 788,875 Rismuller May 2, 1905 1,293,780 Hornsey Feb. 11, 1919 1,295,290 Fasting Feb. 25, 1919 1,309,879 Davids et a] July 15, 1919 1,630,992 Waterman May 31, 1927 1,709,848 Hardinge Apr. 23, 1929 1,985,801 Sheehan Dec. 25, 1984 2,069,174 Nielsen Jan, 26, 1987 FOREIGN PA'I'ENTB Number Country Date 499,807 Germany May 28, 1930 578,728 France July 10, 1924 721,881 France Dec. 28, 1931 786,216 France June 8, 1935 844,187 France Apr. 17, 1999 

